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Plow headlights not working...

Discussion in 'Boss Plows Discussion' started by RamDude01, Oct 9, 2008.

  1. RamDude01

    RamDude01 Member
    Messages: 41

    Hi everyone, been reading and gathering a lot of great info over the past couple of years and am in need of some help. I just installed the wiring in my 98 Dodge Ram 2500 for a used 2003 super duty 8' straight blade, everything seems to work except for the plow headlights. When I hit the headlight switch in the cab from truck to plow, the truck headlights go off but no plow lights coming on... switch it back to truck and the truck lights come back on. Marker lights and turn signals work just fine, goes up, down and angles just fine... anyone have any idea of what could be wrong??? The wiring, I believe, is installed correctly as it is by the book and I had my 01 Dodge sitting next to it for verification. I haven't taken the bulbs out to check them yet but I don't believe that is the problem.

    I think that I also may have noticed a slight spark between the pin spring clip (that holds the pin back while mounting) and the plow frame when I was hooking it up (after hitting the smart hitch 2 button) and trying it out the other night... any thoughts on that. The wiring was used but in good condition. I did not see anything wrong with that anywhere. I haven't tried hooking up to my other plow yet to see if it is a plow side problem or a truck side problem.

    Thanks in advance! http://www.plowsite.com/images/smilies/help.gif
    :help:
     
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Are you positive you have the correct head light adapters (if your application uses them)?

    The spark you saw is due to a poor ground. The plow is attempting to dround through the truck mount as it get near. This is due to a poor ground connection either at the pump motor itself, the truck side ground connection, or at the power connector plug. Start with cleaning the ground cable connections starting at the connecting plug and move your way to the plow. Pull the pump cover off and clean the ground cable where it's attached to the tower.
     
  3. nobletousha13

    nobletousha13 Senior Member
    from VA
    Messages: 124

    check the inline fuse going to the battery. with out that power going to the relays there will be no plow lights. if the fuse is not blown make sure the fuse holder is has not sepereated, meaning the rubber will pull the connections apart just enough to not make a good connection. if thats the problem just smash them back together.
     
  4. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Never hurts to check fuses of course, but if that were the case the truck lights wouldn't go out when the switch was flipped either, which they do, so that means the relays are getting power and at least one of them is being tripped.
     
  5. RamDude01

    RamDude01 Member
    Messages: 41

    Thanks for the input. The truck side grounds should be good. I cleaned all the wiring harness connections before installing on the truck side so I believe those should be good. It didn't require any headlight adapters so those are connected properly. I'll check the fuses also... I am planning on looking more at it tomorrow as the weather is supposed to be better. I'll let you know if I find anything.
     
  6. RamDude01

    RamDude01 Member
    Messages: 41

    Another question... there are four relays, can someone tell me what they are for and which one does what?

    Thanks!
     
  7. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    So this is a used harness? What year/model truck was it removed from? What head light style does your '98 Dodge have? HB1's (9004 bulb) correct?

    You are aware that the vehicle option plug in the plow harness needs flipped 180 degrees for the '94-'02 Dodges with the single HB1's right?
     
  8. RamDude01

    RamDude01 Member
    Messages: 41

    Thanks B&B!

    Yup, the wiring harness was used. I was told that it came off of a Dodge. My 98 has the single headlight bulb so I take it is the HB1. The harness had the correct headlight adapters as they were, just plug and play.

    No, I wasn't aware of the vehicle option plug needing to be flipped. Where might I find that and what exactly would I need to do?

    Thanks again!
     
  9. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    The option connector will be tucked in the harness about a foot or two from the relay pack. Will be a black rubber two wire inline connector. Simply disconnect it, flip it 180 deg and plug it back together.

    Make sure you check the head light fuses afterward as it usually pops the fuses when connected incorrectly.
     
  10. RamDude01

    RamDude01 Member
    Messages: 41

    Thanks again B&B! I'll take a look at it when I get home tonight. Are the headlight fuses you are talking about for the plow headlights or the truck headlights? If they are for the plow lights, where would they be? Sorry to ask so many questions... just not too familiar with the wiring stuff. I take it it must be for the plow lights as the truck lights are still working... thanks again!
     
  11. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    The light fuses I was referring to are for the truck head lights...so if they're working fine I'd say you didn't pop any. :drinkup:
     
  12. RamDude01

    RamDude01 Member
    Messages: 41

    Thanks, I'll try to switch that connector as see what happens... if that doesn't do the trick do you have any other thoughts of where to look?
     
  13. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Only other likey cause would be a bad relay or poor connection in the relay pack causing one of the relays not to switch when you flip the switch.
     
  14. RamDude01

    RamDude01 Member
    Messages: 41

    Thanks B&B for all the help so far. I'll check things out tomorrow and let you know what happens. Have a good one!
     
  15. RamDude01

    RamDude01 Member
    Messages: 41

    Hi B&B, thanks for all the help so far... well, today I checked out the plow. I pulled up to the plow to hook it up and it seemed to act kind of intermittent with the power while hitting the smart hitch 2 button. So I took the cover off on the plow and the ground wire on the motor was a little corroded to I took that off and cleaned it and put it back on. I think that helped with the ground problem...

    I was switching the headlight switch from truck to plow a few times and the low beams finally came on. They switched on and off and seemed to work okay for awhile. High beams would not work on the plow, only low beams. I started looking at the relays, checked the fuse - was good, and started exchanging the relays one by one putting in a relay that I know was good from my other truck. First one, still the same, second one - no headlights, third and fourth - headlights on plow no longer working... so now I am back to no headlights on the plow. I hooked up my 01 truck and the plow lights and everything worked fine. I hooked the 98 truck to the other plow and the same thing, no headlights. So I believe the problem is with the truck side wiring. As far as I can tell, everything is hooked up by the book and I also had my other dodge as the 'template' for where everything went...

    As to the option connector was plugged in the same as my 01, red to white and white to red, so I believe that is the way is should be.

    The other thing that now seems to be happening is when I push the smart hitch 2 button to hitch it up, the relay clicks and there is nothing, just the clicking from the relay. I can manually push the tower up and engage and then when I go to unhitch it, the smart hitch 2 seems to work okay.

    Thanks again for all the advice and help!!!
     
  16. aeronutt

    aeronutt Senior Member
    Messages: 262

    Rather than blindly switching the option plug and blowing fuses, why not look at the schematic and know for certain that you are setting it correctly? You can pull the schematic from the Boss website. I haven't read the Dodge directions, but Chevy had different setups for different year models. Watch out for that...

    EDIT: I just looked up the schematic for Dodges. 2003 & newer with 4 headlights uses standard connection, older with 2 headlights uses reverse. Your connection is correct with red to white & white to red. I'd bet a Big Mac your problem is a bad ground from the relays.

    More EDITS: If you read my original reply, it was wrong. Here's better info...
    For your other questions, there are 4 relays because there are 4 circuits. One switches on the whole system when the key is turned on. The other 3 activate simultaneously to switch Low, High, and Ground from truck to plow when you flip the switch. I just got done reading the schematic and it breaks my truck's original design by crossing both low beams into a single circuit and both high beams into a single circuit. The truck was desiged so that Each headlight is individually fused (4 fuses total) in order to give you the maximum possible lighting options when one fuse pops. Now it has 2 10-amp fuses in parallel that will both pop if something shorts out. I'm not really liking that...

    The Boss wiring harness taps in after the truck fuses, so both the truck's lights and the plow's lights are protected by the truck's fuses. If you blow a headlight fuse it will affect both the truck and the plow. If you have a relay go bad, the relay in question will not switch between truck and plow when the other 3 do. If the bad relay is the one that switches ground, nothing works when you flip the switch. If it's the high or low beam circuit, only the other one will switch. You didn't ask this, but just as fair warning: don't bypass the relay and run both truck and plow lights at the same time because the lights draw about 4-5 amps each. 16-20 amps of lights on two 10 amp fuses = :realmad: when the fuse waits until you are pushing snow to finally give up.

    Did you try taking ALL the relays out of one truck and puting them in the other truck?

    The inline fuse near the battery on the boss wires only protects the relay coils that are activated by the truck/plow dashboard switch and the joystick. If that fuse blows, the truck lights should work normally and the plow won't move at all
     
    Last edited: Oct 11, 2008
  17. RamDude01

    RamDude01 Member
    Messages: 41

    Aeronutt, thanks for the info. I've looked at the schematic as you suggested and the option plug is hooked up correctly. Everything seems to be in order as far as I can tell. The truck lights work normally, low beams and high beams, just nothing on the plow. Like I said, for a short while I actually had low beams working... now again, nothing on either plow.

    Thanks for the clarification on what the relays are for and the suggestion to look at the schematic, that was very useful. Have any thoughts on what the problem could be other than what I've tried?

    Have any thoughts why the relays seem to click, or what else would be clicking, when I hit the smart hitch button to hook it up and why that wouldn't be working to hook it up but seems to work fine to unhook it? This thing is baffling me....
     
  18. sabres07

    sabres07 Senior Member
    from buffalo
    Messages: 110

    Ramdude, I think we have similar problems going on...concurrent threads. I, too, had the lights working yesterday on the plow, but today...nothing. My relays sound like they are clicking, but trucks headlites stay on. In fact, at one point I had the truck and plow lights working at the same time, and when i hit high beams, the truck fuses blew....too much draw. I think I have it isolated to corrosion on the trigger relay or possibly the red/black wire under dash hooked to improper ignition power source. I am still hoping BB can answer that for me....:redbounce
     
  19. aeronutt

    aeronutt Senior Member
    Messages: 262

    It seems like no matter what I'm working on, electrical problems always end up being something far too simple that gets overlooked. Proper grounding and clean contacts end up fixing glitchy gremlins more often than failed components. It took me a few tries to get my previous reply accurate so go back up and re-read it too. I was flat-out wrong when I posted it initially...:dizzy:

    Try pulling all the wires off (especially ground wires under the hood) and buffing the terminals with 400 grit sandpaper to absolutely remove any possible doubt about the quality of the connections. Use plenty of dielectric grease when reassembling to prevent corrosion problems later. If that doesn't get you going, swap ALL the relays from one truck to the other. If that doesn't change anything then about the only thing left is tracing out the wires with a test light or multimeter. It shouldn't come to that though...
     
  20. grassplus

    grassplus Junior Member
    Messages: 13

    Have any thoughts why the relays seem to click, or what else would be clicking, when I hit the smart hitch button to hook it up and why that wouldn't be working to hook it up but seems to work fine to unhook it? This thing is baffling me....

    possibly corroded power and ground cables going between the truck and plow. where they connect together gets worn. if you look inside the connection there is a split on the male contacts. put a small screwdriver in there and split them apart so they make good contact. My V hesitated while hooking up last year and that fixed the problem. (2001 dodge)
     
    Last edited: Oct 12, 2008